Four weeks into the 2017 NFL season, the Buffalo Bills sat atop the AFC East, one game ahead of the scuffling New England Patriots.

Two months later, the Bills are fighting for their playoff lives while the Patriots, winners of seven straight, appear destined for a ninth consecutive division crown.

The longtime rivals will meet for the first time this season Sunday at New Era Field.

New England has imposed its will on Buffalo throughout the Bill Belichick/Tom Brady era and has been especially dominant in the Bills’ home building, losing just once there since 2003 and twice since Brady took over as quarterback in 2001.

Here’s a quick rundown of what to watch for in the latest Pats-Bills matchup:

INJURY REPORT
Wide receiver Chris Hogan (shoulder) and right tackle Marcus Cannon (ankle) both will miss their fourth consecutive game for New England. Eight other Patriots are listed as questionable, including Cannon’s backup, LaAdrian Waddle, and center David Andrews.

If Cannon and Waddle both cannot go, Cameron Fleming likely would start at right tackle for the Patriots. Fleming performed fine as the Pats’ swing tackle in 2016 but has struggled in limited game action this season.

The Bills, meanwhile, will be without wide receiver Kelvin Benjamin, running back Mike Tolbert, tackle Cordy Glenn and guard John Miller.

PATRIOTS’ OFFENSE VS. BILLS’ DEFENSE
Which Bills defense will show up in this game? The one that allowed 135 points in consecutive losses to the New York Jets, New Orleans Saints and Los Angeles Chargers, or the one that held the Kansas City Chiefs to 10 points and Kareem Hunt to 17 yards on 11 carries last weekend?

Buffalo lives on creating turnovers — it’s forced 15 and committed just two in its six wins this season — and likely will need a few of those if it hopes to slow down a Patriots offense that’s scored 41, 33 and 35 points in its last three games.

Patriots quarterback Tom Brady lit it up in November, earning AFC Player of the Month honors, and running back Dion Lewis is coming off his first career 100-yard rushing performance. Lewis and Rex Burkhead have taken the lead in New England’s running back group of late, with James White seeing his role reduced and former Bill Mike Gillislee sitting out the last three games as a healthy scratch.

It’s fair to expect a big game from Rob Gronkowski, who traditionally dominates when playing back in his native western New York. In six career games in Buffalo, the tight end has 35 catches for 583 yards and seven touchdowns.

Brady also has owned the Bills in Buffalo:

Tom Brady has more wins than any Bills QB has in games played in Buffalo in last 12 years. He can tie Drew Bledsoe this week for most wins all-time in Buffalo:

PATRIOTS’ DEFENSE VS. BILLS’ OFFENSE
The Patriots’ depth at linebacker and defensive end looked dicey after Trey Flowers, Marquis Flowers and Kyle Van Noy all sustained injuries in last Sunday’s win over the Miami Dolphins. All three are listed as questionable for this game, but none of them missed practice this week, meaning their injuries are relatively minor.

Running back LeSean McCoy is the Bills’ best offensive player, but the Patriots could have a tough time defending quarterback Tyrod Taylor after struggling against mobile QBs earlier this season. Taylor is elusive, can run and doesn’t turn the ball over — his three interceptions this season equaling Brady’s total.

Taylor’s receiving corps isn’t particularly formidable, though, as tight end Charles Clay leads the Bills in receiving yards while McCoy paces them in catches. Rookie Zay Jones has improved in the second half of the season but remains inconsistent, recording catches on just 37.7 percent of his targets.

Patriots cornerback Stephon Gilmore will look to continue his strong play in his first game back in Buffalo. The ex-Bills corner arguably has been New England’s best defensive back in his three games since returning from a concussion.